Upgrading the Proxmox VE server hosting my router

I recently upgraded all my Proxmox VE servers from version 7 to 8 — which was a straight forward and easy process. But one server presented a challenge; the hypervisor running my router. How to apt dist-upgrade with the router down?

It turned out to be very easy, here is how 👇

With the router VM running; I first ran the check list script, dealt with any warnings, and made sure the current version was fully up to date:

sudo pve7to8
sudo apt update
sudo apt dist-upgrade

Then it was time to update the repository definitions and download all resources:

sudo sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list
sudo apt update
sudo apt dist-upgrade --download-only

The key here is --download-only, download all updates but don’t apply them.

Now the router VM, and any other VMs, can be shut down and the upgrade applied:

sudo apt dist-upgrade

When complete, I rebooted, removed any unused dependencies and checked the system log for any errors or problems:

sudo reboot
sudo apt autoremove
sudo journalctl -k

Worked as a charm 🖖

Proxmox Wiki: Upgrade from 7 to 8